Imagine sleeping seven stories underground in a cave or watching fish swim past the window of your room. Sound a bit farfetched? Not to the owners of Kokopelli's Cave Bed & Breakfast in New Mexico or the creators of Jules' Undersea Lodge in Florida. In fact, all 11 of our extraordinary hotels have become successful businesses by allowing guests to trade in the daily grind for a world of adventure and mystique.

The hotels included in our slideshow cater to unusual niches, drawing travelers from the world over. There's something unique about each of them that entices curious vacationers to make the extra effort to get there, whether that means taking a floatplane or climbing 50 feet above the wilderness to sleep amid the trees.

Nurture your adventurous side as we take you on a tour of some of the world's most extraordinary hotels.--Kristin Edelhauser

How it came to be: Named after Jules Verne, this undersea lodge actually began as La Chalupa research laboratory, an underwater habitat researchers used to explore the marine environment off the coast of Puerto Rico. Koblick and Monney created the hotel to make the experience of living underwater open to the general public, though the research lab remains in operation.

Why it's extraordinary: This lodge is the only underwater hotel in the world, in addition to being the first underwater research lab accessible to the average person. But getting to the hotel is no easy feat. Guests must scuba-dive 21 feet below sea level to get to the hotel's entrance at the bottom of the habitat. Once inside, guests can enjoy the comforts of a typical hotel room, including air-conditioning, hot showers and DVD players. The lodge can host two sets of couples, each with their own private bedroom, but the rest of the facility is shared. If you're not a pro diver, it's not a problem; the lodge also offers certification courses.

Kokopelli's Cave Bed & Breakfast

How it came to be: The bed and breakfast started as a geological office for the owner, Bruce Black, who used it for his oil and gas company, Black Oil. When it didn't work out as an office space, the Black family began using it for family getaways, eventually turning it into the popular bed and breakfast it is today.

Why it's extraordinary: Kokopelli's Cave is built into a 65-million-year-old sandstone formation nearly 70 feet, or seven stories, underground. Inside this 1,650-square-foot, one-bedroom cave, you'll find two balconies, a carpeted living area, a Jacuzzi tub, waterfall shower and other amenities to make you feel at home. When you're not marveling at the cave itself, the surrounding area offers 400 acres of hiking, biking and exploring.

How it came to be: Smith says he and his partner wanted to create the perfect place for snowboarders. "We wanted to come up with the kind of place snowboarders would crawl through broken glass to get to, and we did it."

Why it's extraordinary: THE BLOCK is the first hotel chain catering specifically to snowboarders. In addition, these hotels have something none of the others on this list have: their own reality show. Last year, the network G4 began filming episodes of the reality show, THE BLOCK, featuring the crew of both hotels and giving viewers a glimpse into the snowboarding lifestyle. The buzz created from the show seems to be helping business; Smith says he already has plans to open two more BLOCK hotels, including one at Mammoth Mountain in California and one in Breckenridge, Colorado.

Sabi Sabi Private Game Reserve

Where the elephants roam

Location: Mpumalanga, South AfricaOwners: Hilton and Jacqui LoonFirst year of business: 1979Number of employees: About 200Starting room rate: $1,352 per person for a three-night, all-inclusive package

How it came to be: Sabi Sabi's beginnings date back to 1830, when European hunters first established a camp on the south bank of the Sabie River. By 1920, recreational rail travel into the area became popular, and game viewing from the railway coach was made possible. In 1979, the Loons formed the present Sabi Sabi company and purchased the land that is now home to the four private lodges that make up the game reserve.

Why it's extraordinary: Where else can you go on a safari in an open Land Rover by day and night, viewing and learning about 300 bird and 200 animal species, including lions, leopards, rhinos, elephants and cheetahs? At Sabi Sabi Private Game Reserve, guests tag along with specially trained game rangers and trackers as they explore the African bush. Not only do guests get to view extraordinary animals, but they also stay in luxurious, air-conditioned, award-winning lodges. Notable guests include tennis-star Anna Kournikova, golf-pro Phil Mickelson and actor Wesley Snipes.

Gaia Napa Valley Hotel and Spa

How it came to be: The owner, Wen-I Chang, wanted to make a difference in the world. He decided that building the first fully environmentally sustainable hotel could impact both guests and the community in a positive way.

Why it's extraordinary: Even in the building stages of Gaia Napa Valley, Chang used recycled materials whenever possible, in addition to chemical-free landscaping. The hotel also uses energy-efficient heating, ventilating and air conditioning, water conservation features and solar panels. This eco-operational hotel is doing its part to protect the environment while offering guests beautiful and relaxing sites, including a tranquil swan lake and Balinese-style spa.

Library Hotel

The book on luxury

Location: New York CityOwner: Henry KallanFirst year of business: 2000Number of employees: 35 to 40Starting room rate: $279

How it came to be: The Library Hotel was inspired by the New York Public Library, which is located just steps away, and the Pierpont Morgan Library, located three blocks away. Hotelier Kallan wanted to create a unique space, and by working with an architect, he was able to make his vision a reality.

Why it's extraordinary: The Library Hotel is the first hotel to offer guests more than 6,000 volumes organized throughout the hotel's 10 floors by the Dewey Decimal System. Guests can request a room on a floor that fits their own taste in books. On the Literature floor, for example, guests can find rooms featuring poetry, the classics or even erotic literature. Speaking of which, Dr. Ruth Westheimer is the curator of the Love Room. Guests seen on the property include, quite fittingly, authors James Patterson, John Grisham and Erica Jong.

Wigwam Motel

A native community

Location: Rialto, California on Historic Route 66Owners: Currently, the Wigwam Motel is owned by Jagdish and Ramila Patel, but it was originally created by entrepreneur Frank RedfordFirst year of business: 1949Number of employees: 8Starting room rate: $60

How it came to be: In 1934, Redford parlayed his interest in Native American history into a business when he built the first teepee village of the Wigwam Motel chain in Horse City, Kentucky. In 1937, he patented his idea and built a second village in Cave City, Kentucky. By the early 1950s, seven wigwam villages had been built in the Southern and Southwestern United States, including the village in Rialto.

Why it's extraordinary: By the 1960s and 1970s, the golden age of roadtrips and Americana had dwindled. As a result, today only two other Wigwam Motels remain: one on Route 66 in Holbrook, Arizona and the Cave City location. The motel features a village-style arrangement of 19 30-foot-tall teepees made of concrete and wood. Each wigwam is equipped with the essentials, and the grounds include an outdoor barbecue grill and swimming pool. You may have noticed a replica of the Wigwam Motel in Disney/Pixar film, Cars, which was set on Historic Route 66 in California.

King Pacific Lodge

A diamond in the wilderness

Location: Princess Royal Island, British ColumbiaOwner: Hideo "Joe" MoritaFirst year of business: 2000Number of employees: 47Starting room rate: $3,842 per person for a three-night, all-inclusive package

How it came to be: King Pacific Lodge was built to create a hotel where guests could experience the area's beautiful natural surroundings without negatively impacting the environment. So the lodge was built atop a barge and is towed in to Princess Royal Island from May to October. You can only get to the floating hotel by taking a floatplane from Bella Bella.

Why it's extraordinary: Guests can experience pristine wilderness in the comfort of Five Star accommodations. From whale-watching in waters with one of the world's highest densities of orcas and humpbacks, to fly-fishing at untouched areas only accessible by helicopter, there's no limit to the ways guests can immerse themselves in the nature surrounding the lodge. To be true to the goal of ecologically responsible tourism, the lodge recently announced a plan to reduce its carbon footprint by 50 percent over the next five years. One celebrity guest seen on the remote floating hotel: Kevin Costner.

Cedar Creek Treehouse

How it came to be: Compher built the Cedar Creek Treehouse in 1982, but didn't open it to guests until 1998. He later added a Treehouse Observatory to provide guests with spectacular mountain views from 100 feet in a nearby fir tree. To reach the treehouse, you must first make your way across an 80-foot-long suspension footbridge through a rainforest of cedars and evergreens and then ascend a five-story stairwell.

Why it's extraordinary: You'll likely bring out your inner child by staying 50 feet in the air in this bed and breakfast cottage. Cedar Creek Treehouse can accommodate up to five people, with additional space on the stairwell observation floor and numerous camping spots below. Not into roughing it? That's OK. This mountain retreat includes 12-volt electric lights, water, a gas stove, an icebox and sink in the kitchen, and a toilet and wash basin in the bathroom.

How it came to be: The inspiration for the Ice Hotel Quebec-Canada came from the original ICEHOTEL built in Sweden. Desbois, known to many as "Mr. Igloo," decided that if Sweden could build a hotel out of ice, so could Quebec, "the snow capital of the world." He traveled to a tiny village in Sweden to meet with the creators and learn from them. Desbois went on to form Le Piste Desbois, the only business in Canada specializing in making and managing igloo villages.

Why it's extraordinary: It can boast being the only ice hotel in the Americas. But it may not be the only one for long; Desbois plans to partner with the original ICEHOTEL in Sweden to create a third location somewhere in Western North America. Each year, the architecture of the hotel changes as talented artists and ice sculptors create new, intricate designs, which is no small effort. Construction lasts for about five weeks and involves 15,000 tons of snow and 500 tons of ice to build the structure, including 18-foot-high ceilings. Sculptors create everything from exquisite furniture made of pure ice, to elaborate ice candelabras hanging from the high ceilings. After a season lasting from January to April, the Ice Hotel melts away and begins preparing for the following year.

CUBE Hotels

An adventure-seeker's playground

Location: Carinthia, Austria and Graubünden, SwitzerlandOwner: Rudolf TucekFirst year of business: 2004 for Austria; 2005 for SwitzerlandNumber of employees: 121 between both locationsStarting room rate: $72 in Austria; $87 in Switzerland

How it came to be: The goal of CUBE Hotels is to make alpine tourism attractive and affordable in both summer and winter. The main target is young, adventure-hungry sport enthusiasts. CUBE NASSFELD in Austria and CUBE SAVOGNIN in Switzerland are both located at the base stations of their respective local ski lifts.

Why it's extraordinary: The CUBE hotels combine unusual architecture and urban design set in the picturesque and scenic backdrop of the Alps. Tucek says CUBE is the perfect blend of sport, entertainment, design and community. With rooms for two, four, six or eight, CUBE offers private or communal areas based on your budget. The rooms also feature a "showroom" that can be used to store guests' extreme sports gear with proper ventilation and heating in the winter. Though most guests are on the go, the hotels do allow for some R&R in the CUBE Relax Area, which includes a steam bath, massage and quiet area, in addition to a 24-hour bar and club. The concept seems to be catching on: CUBE BIBERWIER-LERMOOS, also in Austria, is set to open in July.